Natural attenuation of naphthalene and benzene at a former gasworks site

Naphthalene and benzene are ubiquitously found at former gasworks sites. In order to demonstrate that monitored natural attenuation (MNA) is an alternative strategy for remediation of groundwater at the investigated site, biodegradation was characterized by: (1) reduction of contaminants; (2) correlation of contaminants concentration changes with geochemical parameters; (3) enumeration of anaerobic microorganisms and correlation with geochemical data; (4) laboratory assays with site-specific enrichment cultures and naphthalene as the sole carbon source and electron donor; (5) modeling plume extension of naphthalene along the centerline and (6) carbon stable isotope (CSIA) analysis. The study demonstrated that naphthalene attenuation mainly depends on high sorption on aquifer material. In contrast, benzene is predominantly attenuated by biodegradation.